| Z1 | Z2 | Z3 | Z4 |
Reducing-sulfate bacteria (UFC/ml) | ||||
15 | 0 | 0 | 14.96 | 0 |
30 | 0 | 0 | 13.75 | 0 |
45 | 0 | 0 | 19.91 | 0 |
60 | 0 | 0 | 22.91 | 0 |
75 | 0 | 0 | 18.21 | 0 |
90 | 0 | 0 | 18.22 | 0 |